Java Reflection Generic Return Type getGenericReturnTypeOfGenericInterfaceMethod( Class clazz, Method method)

Description

Given an interface Method, look in the implementing class for the method that implements the interface's method to obtain generic type information.

License

Open Source License

Parameter

Parameter	Description
clazz	a parameter
method	interface method

Declaration

public static Type getGenericReturnTypeOfGenericInterfaceMethod(
        Class clazz, Method method) 

Method Source Code

//package com.java2s;
/*******************************************************************************
 * QMetry Automation Framework provides a powerful and versatile platform to
 * author//w  w  w  .  j  av  a2  s  .c om
 * Automated Test Cases in Behavior Driven, Keyword Driven or Code Driven
 * approach
 * Copyright 2016 Infostretch Corporation
 * This program is free software: you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation, either version 3 of the License, or any later version.
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
 * details.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT
 * OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE
 * You should have received a copy of the GNU General Public License along with
 * this program in the name of LICENSE.txt in the root folder of the
 * distribution. If not, see https://opensource.org/licenses/gpl-3.0.html
 * See the NOTICE.TXT file in root folder of this source files distribution
 * for additional information regarding copyright ownership and licenses
 * of other open source software / files used by QMetry Automation Framework.
 * For any inquiry or need additional information, please contact
 * support-qaf@infostretch.com
 *******************************************************************************/

import java.lang.reflect.Method;

import java.lang.reflect.Type;

public class Main {
    /**
     * Given an interface Method, look in the implementing class for the method
     * that implements the interface's method to obtain generic type
     * information. This is useful for templatized interfaces like:
     * <p/>
     * 
     * <pre>
     * interface Foo&lt;T&gt; {
     *    &#064;GET
     *    List&lt;T&gt; get();
     * }
     * </pre>
     * 
     * @param clazz
     * @param method
     *            interface method
     * @return
     */
    public static Type getGenericReturnTypeOfGenericInterfaceMethod(
            Class clazz, Method method) {
        if (!method.getDeclaringClass().isInterface()) {
            return method.getGenericReturnType();
        }

        try {
            Method tmp = clazz.getMethod(method.getName(),
                    method.getParameterTypes());
            return tmp.getGenericReturnType();
        } catch (NoSuchMethodException e) {

        }
        return method.getGenericReturnType();
    }

    /**
     * Get all methods of the class including parent.
     * 
     * @param clazz
     * @param name
     *            case-insensitive method name to get
     * @return
     * @throws NoSuchMethodException
     */
    public static Method getMethod(Class<?> clazz, String name)
            throws NoSuchMethodException {
        Method[] methods = clazz.getMethods();
        for (Method m : methods) {
            if (m.getName().equalsIgnoreCase(name)) {
                return m;
            }
        }
        if (null != clazz.getSuperclass()) {
            getMethod(clazz.getSuperclass(), name);
        }
        throw new NoSuchMethodException();
    }
}

Related

1. getGenericClassFromMethodReturn(Method m)
2. getGenericReturnClass(Method method)
3. getGenericReturnType(Method m)
4. getGenericReturnTypeMap(Method method, boolean isAllowNull)
5. getGenericReturnTypeOfGenericInterfaceMethod(Class clazz, Method method)
6. getGenericType(Type returnType, int index)